Further studies needed to justify robot-assisted surgery

5th July 2013

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After conducting a review of the available data, Hani Marcus (The Hamlyn Centre for Robotic Surgery, Imperial College London, UK) and others reported in the European Spine Journal that—given the high cost of robotic systems—further high-quality studies are required to justify the use of robotic-assisted pedicle screw placement (SpineAssist, Mazor Robotics) because the current evidence is insufficient.

Marcus et al commented that surgical misplacement of pedicle screws could result in serious morbidity and that studies favour the use of image-guided systems (eg. fluoroscopy) to improve accuracy of placement. They added: “A miniature spine-mounted robot has recently been developed to further improve the accuracy of pedicle screw placement”. The purpose of the European Spine Journal review was to examine the evidence for robotic-assisted pedicle screw placement to evaluate whether it “offers an advantage over conventional fluoroscopy-guided procedures in terms of pedicle screw position.”

The authors searched for studies (using the Cochrane Central Register of Controlled Trials among other sources) that compared the use of the robotic system with the use of conventional fluoroscopy, assessed outcome in terms of pedicle screw position and presented “sufficient data in each arm to enable meaningful comparison”. Of 22 studies that featured data for both robot-assisted and fluoroscopy-guided pedicle screw placement, only five met the review’s search criteria. The five remaining studies in the review included two randomised controlled trials, one prospective cohort, one retrospective cohort, and one cadaveric study. Overall, data were available for 1,308 pedicle screws (729 using robotic assistance and 579 using fluoroscopy guidance).

Marcus et al reported that one study favoured fluoroscopy-guided placement regarding pedicle screw placement whereas the other four favoured robot-assisted placement (“albeit often not reaching statistical significance”, they commented). None of the three studies that reviewed duration of surgery found any significant differences between the two techniques. All of the studies assessed radiation exposure, with two finding that robot-assisted surgery significantly reduced radiation exposure, two finding no significant differences between the robotic system and fluoroscopy, and one—which did not perform a statistical comparison—showing a trend towards reduced exposure with robot-assisted surgery.

According to the authors, the evidence for robot-assisted screw placement is “limited and inconclusive”. They added as the results of the studies in the review were “mixed”, there was “insufficient evidence to unequivocally recommend one surgical technique over the other.” Marcus and others concluded: “Given the high risk of spinal surgery, the high cost of robotic systems, further studies to justify the clinical benefit and healthcare economics [of the robotic system] are required.”

Marcus told Spinal News International: “While there can be no innovation without evaluation, we must remember that the field of surgical robotics remains young and we should not hastily dismiss absence of evidence as evidence of absence of benefit. Arguably the greatest role for current generation surgical robots such as SpineAssist are as a ‘great leveller’, allowing less experienced surgeons to perform complex surgery, but further studies are necessary to prove safety and efficacy before widespread adoption of such platforms.”